Provided is a cleaning blade including an elastic member configured to abut on a surface of a cleaning target member and remove residual material deposited thereon, wherein elastic member satisfies requirements a to c below, a. an abutment part of the elastic member to abut on the surface of the cleaning target member has a reformed layer, b. Martens hardness at a surface of the reformed layer is from 1.5 to 15 N/mm.sup.2, and c. a relationship H/L between maximum Martens hardness H among Martens hardnesses H in a region inward from the abutment part thicknesswise and distance L from the surface of the reformed layer is from 0.010 to 0.2 (N/mm.sup.2.Math.1/μm), where distance L represents minimum distance among distances to the surface of the reformed layer, from positions at which a measured Martens hardness and a measured elastic power are equal to those of the elastic member.

The present disclosure provides a cleaning blade (2) that prevents toner from slipping through the cleaning blade in a long time use. The cleaning blade (2) is used to remove residual toner remaining on a surface of a counterpart member (1) in an electrophotographic image forming device by sliding contact with the counterpart member (1). The cleaning blade (2) includes a support (3) including a plate-shaped portion (31); and a blade part (4) made of polyurethane, and joined to the plate-shaped portion (31) in integral forming. The blade part (4) includes a plate-shaped blade body portion (41) that is joined to a plate surface of the plate-shaped portion (31), and a reinforcing portion (42) that extends from a surface of the blade body portion (41) and is joined to a front end face of the plate-shaped portion (31). The reinforcing portion (42) has a curved surface (421) that curves inward.

Provided is a cleaning blade disposed to be in contact with an image carrying belt having an elastic layer for removing foreign material from a surface of the image carrying belt, including: a base; and an amorphous coating layer on the base, the coating layer including a contact portion disposed to be in contact with the image carrying belt, wherein the contact portion is curved to have a predetermined curvature with respect to a direction of a movement of the image carrying belt.

A cleaning blade (1) having an elastic body (11) molded from a rubber base material, and having at least a surface treatment layer (12) on the area of the elastic body (11) that is brought into contact with a body to be contacted, wherein the surface treatment layer (12) is formed by impregnating the surface layer portion of the elastic body (11) with a surface treatment liquid containing an isocyanate compound and an organic solvent and hardening the liquid. The elasticity modulus of the surface treatment layer (12) is 40 MPa or less, the elasticity modulus of the elastic body (11) is 3-20 MPa, and the difference between the elasticity modulus of the surface treatment layer (12) and the elasticity modulus of the elastic body (11) is 1 MPa or more.

The present invention addresses the issue of providing a cleaning blade having excellent durability. An elastic body for blades is provided that has an abutting section that comprises a heat-curable polyurethane urea that is a reaction product of at least a polyol, a polyisocyanate, and a curing agent including a diaminobenzoic acid ester indicated by general formula (1).

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Toner contains toner base particles and an organosilicon polymer on the surface of the toner base particles, and silica particles are added to the toner as an external additive. The surface roughness Rz of an intermediate transfer belt, against which a blade abuts, in the width direction of the intermediate transfer belt perpendicular to the belt conveying direction is larger than the average particle diameter Ry of the organosilicon polymer and is smaller than the average particle diameter Rk of the silica particles.

Toner contains toner base particles and an organosilicon polymer on the surface of the toner base particles. After a toner image is transferred from an intermediate transfer belt to a transfer material, residual toner on the intermediate transfer belt is collected into a belt cleaning device by a blade. A CPU executes supply control of supplying toner from a developing device toward the blade via a photosensitive drum and via the intermediate transfer belt on the basis of the counter accumulated value that correlates with the amount of organosilicon polymer adhering to the blade.

An image forming apparatus is provided. The image forming apparatus includes an image bearer and a cleaning blade configured to remove toner particles remaining on the image bearer. The cleaning blade includes an elastic member in contact with a surface of the image bearer to remove the toner particles. The elastic member has a Martens hardness of from 3 to 8 N/mm.sup.2 when measured by a nanoindentation method with a load of 1 μN. The toner particles comprise toner base particles and an external additive, and the external additive comprise silica particles. A liberation ratio (Xs) of the silica particles liberated from the toner particles is from 40% to 75% when measured by an ultrasonic vibration method. A proportion (R70) of the silica particles having a volume-based particle diameter of 70 nm or more in the silica particles liberated from the toner particles is from 70% to 90% by number.

An external additive for toner, wherein the external additive is an organosilicon polymer particle, and defining A (nm) as the number-average particle diameter of primary particles of the external additive measured using a scanning electron microscope, and defining B (nm) as the number-average particle diameter of the external additive measured in accordance with a centrifugal sedimentation method, the A and the B satisfy a following Expression (1):

1.5≤B/A≤3.0  (1).

An electrophotographic cleaning blade comprising: an elastic member containing polyurethane; and a support member supporting the elastic member, and cleaning a surface of a member to be cleaned in motion, by contact of part of the elastic member against the surface of the member to be cleaned, wherein the elastic member has, at least on the tip side, a plate shape having a main surface facing the member to be cleaned and a leading end surface that forms a tip side edge together with the main surface, and a coefficient of variation of area ratios of white regions in each of sections of a binarized image created from grayscale phase image obtained from the leading end surface, is 20.00 or less, and a value of HM1-HM2 is larger than 0.10 N/mm.sup.2.